A well system (e.g., oil or gas wells for extracting fluids or gas from a subterranean formation) can include, among other components, interconnected pipes, valves, or tubes in a wellbore. While operating a well, an event may occur (for example, a wellbore wall may collapse) that can cause a component to become trapped in the wellbore. It can be desirable to salvage as much of the component as possible. One method of salvaging components stuck downhole is by severing, typically through the use of an explosive device, the component at a point above the location where the component is trapped. If successful, the free portion of the component can then be withdrawn from the wellbore. It can be challenging, however, to sever well components downhole adequately.